An element is a pure substance that cannot be broken down into simpler substances by chemical or physical methods. An element is a substance that is composed of only atoms of the same type of atom i.e. atoms with the same number of protons in their nuclei.
Only 92 elements occur naturally– number 1 is hydrogen, number 92 is uranium. About 24 ‘artificial’ elements have been produced in laboratories. The Elements are arranged in the Periodic Table, on page 44 of the Mathematics Tables. The elements are represented by symbols. The 1st 2 elements Hydrogen & Helium make up the most of the atoms in the universe. There are over 10 million different known pure substances.
Only 116 are elements; all the others are compounds. Like 26 letters in the Alphabet but millions of words!!!
Non-metallic Elements: Names, Symbols Note location of the non-metals in the Periodic Table (metal steps).
* Can show metallic properties
Burns with a ‘pop’
Relights a glowing splint
blue cobalt chloride pink
The elements of a compound always occur in fixed ratio of mass. In water hydrogen is always one ninth of the total mass and oxygen is always eight ninths. The mass ratio of hydrogen to oxygen is always 1:8 in water.
About 80% of the elements are Metals. In the Periodic Table the metals are to the left of a zig-zag line formed by B, Si, As, Te and At.
Some Metallic Elements: Names, Symbols, Uses
The General Properties of Metals 1. Lustrous i.e. shiny. 2. Good conductors of heat.
3. Malleable i.e. able to be hammered or pressed into new shape without breaking or cracking.
4. Ductile i.e. capable of being drawn out or stretched into a thin wire.
5. Good conductors of electricity. 6. Lose electrons, becoming positive ions in chemical reactions.
7. Sonorous, make a ringing sound when struck.